Provided are stevioside sweeteners having a high purity. As the results of breeding through crossing and selecting and DNA testing, varieties of Stevia rebaudiana bertoni are identified. By crossing these varieties, a novel variety which enables continuous cultivation of the specific variety is developed (Deposition No. FERM BP-10870). By extracting dry leaves of this variety, a sweet component containing stevioside at a high concentration can be obtained in a stable state. From this extract, various favorable stevioside sweeteners can be produced.
